Ambient monitoring measures the status of air quality throughout the state to assess trends, compliance with federal and state air quality standards, effectiveness of control strategies and attainment plans, health effects and environmental damage; respond to citizen complaints; evaluate specific geographic or hot-spot air quality concerns; and create environmental indicators. Emission inventory is the cataloging of sources of air pollution and the emissions from those sources. Inventory data are critical to the understanding of the causes of air pollution problems and creation of appropriate solutions. Meteorological forecasting and dispersion modeling of air pollutants are essential to understanding the movement and buildup of air pollution; the carrying capacity of airsheds; the interaction of pollutants; and the location of maximum impact of sources of pollution. As of September 26, 2005 there are no longer any areas of Washington designated as "NONATTAINMENT."